Copolymers of ethylene with vinyl monomers, methods of their production and application

ABSTRACT

Copolymers of ethylene with vinyl monomers, which are derivatives of vinyltin of the general formula CH2 CHSnR1R2R3, where R1, R2, R3 are the same or different radicals: alkyls with the number of carbon atoms from one to six, or phenyl, the content of (-CH2-CH(SnR1R2R3)-) links in the copolymer being 1-30 mol.%, and that of (-CH2-CH2-) links, 99-70 mol.%. Said copolymers are produced by a method which consists in copolymerizing ethylene with derivatives of vinyltin of the above-specified general formula, at a molar ratio of ethylene to organovinyltin monomers equal to 20-98:80-2 respectively, under a pressure of 50-3000 atm, at a temperature of 50-300*C, in the presence of initiators of free-radical type. The copolymers thus produced can be used as antiwear additions to lubricants.

Samoilov et al.

3,859,220 Jan. 7,1975

COPOLYMERS OF ETHYLENE WITH VINYL MONOMERS, METHODS OF THEIR PRODUCTION AND APPLICATION Inventors: Sergei Mikhailovich Samoilov,

Simonovsky val, 8. kv. 60; Nikolai Alfredovich Plate, Novoslobodskaya ulitsa, 67/69, kv. 93; Vadim Vasilievich Maltsev, ulitsa Matveevskaya, l0, korpus 2, kv. 169; Viktor Nikolaevich Monastyrsky, ulitsa Vasilievskaya, 9, kv. 62, all of Moscow, U.S.S.R.; Valentin Alexeevich Kargin, deceased, late of ulitsa Arkadia Gaidara, 7, kv. 4, Moscow, U.S.S.R. by Kaleria Petrovna Velichko, heiress Filed: Jan. 14, 1974 Appl. No.: 432,828

Related U.S. Application Data Continuation of Ser. No. 216,293, Jan. 7, 1972, abandoned, which is a division of Ser. No. 74,525, Sept. 22, 1970, Pat. No. 3,804,816.

U.S. Cl. 252/49.7 Int. Cl Cl0m 1/54 Field of Search 252/49.7

[56] References Cited UNITED STATES PATENTS 2,236,910 4/l94l Lincoln et al 252/497 X 2,334,566 ll/l943 Lincoln et al 3,245,907 4/l966 Stark et al.

R26,407 6/l968 Butler 252/497 X Primary Examiner-W. Cannon Attorney, Agent, or Firm-Holman & Stern [57] ABSTRACT Copolymers of.ethylene with vinyl monomers, which are derivatives of vinyltin of the general formula CH =CHSnR R R where R,, R R are the same or different radicals: alkyls with the number of carbon atoms from one to six, or phenyl, the content of [CH -CH(SnR,R R links in the copolymer being 1-30 mol.%, and that of [CH CH links, 99-70 mol.%. Said copolymers are produced by a method which consists in copolymerizing ethylene with derivatives of vinyltin of the above-specified general formula, at a molar ratio of ethylene to organovinyltin monomers equal to 20-98:80-2 respectively, under a pressure of 50-3000 atm, at a temperature of 50300C, in the presence of initiators of free-radical type.

The copolymers thus produced can be used as antiwear additions to lubricants.

1 Claim, No Drawings COPOLYMERS OF ETHYLENE WITH VINYL MONOMERS, METHODS OF THEIR PRODUCTION AND APPLICATION This is a continuation of application Ser. No. 216,293, filed Jan. 7, 1972 now abandoned, which in turn is a divisional under Rule 60 of Ser. No. 74,525, filed Sept. 22, 1970, now US. Pat. No. 3,804,816 issued Apr. 16, 1974.

The present invention relates to copolymers of ethylene with vinyl monomers, to methods of their produc- 'ing and to application thereof.

Known in the art are copolymers of ethylene with oxygen-containing vinyl monomers, such as vinyl acetate or ethyl acrylate, which are produced by copolymerizing ethylene with said vinyl monomers under a pressure of 50-3000 atm, at a temperature of 50300C, in the presence of initiators of free-radical type (cf. Raff R.A.V., Doak K.W., Crystalline Olefin Polymers, High Polymers, vol. XX, p. 337; lnterscience Publishers, .1. Wiley, N.Y., London, Sydney, 1965).

The known copolymers of ethylene with vinyl monomers are used in various branches of industry, e.g., as additions, improving the viscous properties of lubricants.

However, said copolymers of ethylene do not feature antiwear properties and thus cannot be used as additions to lubricants.

The object of the present invention is to provide new kinds of copolymers of ethylene with vinyl monomers, which would feature properties of antiwear additions for lubricants, and also to provide a method of producing such copolymers.

In accordance with said and other objects, the present invention consists in the use of copolymers of'ethylene with derivatives of vinyltin of the general formula CH =CHSnR R R where R R R are the same or different radicals: alkyls with the number of carbon atoms from one to six, or phenyl, the content of'links [-CH CH(SnR R R in the copolymer being 1-30 mol.%, and that of links [Cl-I -CH being 9970 mol.%.

The herein-proposed stanniferous copolymers of ethylene can be produced by a method, consisting in that ethylene is copolymerized with vinyl monomers under a pressure of 503,000 atm, at a temperature of 50-300C, in the presence of initiators of free-radical type. In said method, according to the invention, as vinyl monomers use is made of derivatives of vinyltin of the general formula Cl-l =Cl-lSnR R,R where R R R are the same or different radicals: alkyls with the number of carbon atoms from one to six, or phenyl, the organovinyltin monomers and ethylene being taken in a molar ratio equal to 280:98-20 respectively.

As pointed out above, the copolymers of ethylene with derivatives of vinyltin can be used for enhancing the antiwear properties of lubricants.

The method of producing copolymers of ethylene with derivatives of vinyltin is effected as follows.

Ethylene is copolymerized with vinyltin derivatives of the above-specified formula under a pressure of 503,000 atm and at a temperature of 50-300C, with the use of free-radical initiators (such as peroxides, azo-compounds, etc.). The copolymerization is carried out either in block, without recourse to solvents, or in a solution of organic compounds: benzene, xylene, chlorobenzene, tetrahydrofuran, etc.

For copolymerization ethylene is employed, which contains not more than 0.001 vol.% of oxygen.

The organovinyltin monomers and an initiator (in case of block copolymerization), or the organovinyltin monomers, an initiator, and an organic solvent (in case the copolymerization in carried out in a solvent medium) are charged into an autoclave in a stream of ethylene. The organovinyl monomers and ethylene are taken in a molar ratio of 2-80z98-20 respectively. The copolymerization proceeds during 5-320 minutes. During the reaction the pressure and temperature are maintained constant with an accuracy of 0 atm and -*.:2C. On completion of the reaction, the reaction mixture is discharged from the autoclave, through a system of traps, in which polymer products are accumulated. The latter are used either without purification, or are purified from the unreacted organovinyltin monomer and mechanical admixtures. The purification is carried out by dissolving the copolymers under heating in benzene, xylene, toluene, or in other solvents, the concentration of the resulting solution being 10-50 wt.% for the copolymer. Then the solution is filtered at a temperature of -120C, and the copolymers are precipitated in a three-sixfold amount (in relation to the volume of the solvent) of acetone, alcohol, or other precipitants at room temperature. The precipitate is filtered off or centrifuged and dried at a temperature of 2070C to constant'weight.

For testing the copolymers as antiwear additions to lubricants, the copolymers are dissolved at a temperature of 60-1 50C and, under stirring, in a lubricant, till the content of the copolymers in the lubricant becomes 0.5-10 wt.%. The tests of lubricants with additions are carried out on a four-ball friction tester with steel balls 12.7 mm in diameter, over a period of time from 5 seconds to 2 hours, at a temperature of 0250C and under a load on the shaft of 15-90 kg. The results of the tests are judged by the magnitude of thewear spot on the balls. Thus, when using a lubricating oil comprising a copolymer, the diameter of the wear spot on the ball is 1.5-2.5 times less than when using the lubricating oil without the copolymer additions.

For a better understandingof the present invention, given hereinbelow are examples, illustrating the producing of copolymers of ethylene with vinyltin derivatives.

EXAMPLE 1 A solution of 2 g of di-tert.-butyl peroxide in 96 g of vinyltriethyltin was charged in a stream of ethylene into a rocking autoclave of 100 cu. cm. capacity, preheated to C. Use was made of ethylene, containing 0.0007 vol.% of oxygen, and the autoclave was blown with ethylene till the content of oxygen became 0.0009 vol%. The pressure of ethylene was raised up to 1,400 atm, and the process of copolymerization was carried out during 20 minutes at a temperature of 160C. During the entire process, the pressure in the autoclave was maintained to be equal to 1,400 atm by adding ethylene after each 50 atm pressure drop. The content of vinyltriethyltin in the mixture of monomers was 75 mol.%.

and then the copolymer was precipitated in 800 ml of acetone at room temperature. The precipitate was separated by centrifugation and dried to constant weight at a temperature of 50C and a residual pressure of 2-5 mm Hg.

There were obtained 1 1.5 g of a sticky wax-like product of pale-grey colour, which was soluble in benzene, xylene, toluene and lubricating oils. The copolymer contained 64.81 wt.% of carbon and 11.37 wt.% of hy drogen; the mineral residue after the combustion was 31.5 wt.%. The copolymer contained 46.9 wt.% (9.6 mol.%) of [CH -Cl-lSn(C H links, and had a molecular weight of 1,770 (as determined cryoscopically in a solution of naphthalene). The presence of said links in the copolymer was confirmed by the IR spectrum (by the absorption of the Sn-C bond at 508 and 668 cm).

The copolymer was dissolved, at a temperature of 80C and under stirring, in a mineral lubricating oil (the viscosity of the oil being 64 and 1 1 cs. at temperatures of 50 and 100C respectively) to the content of the copolymer in the oil of 1 or 2.5 wt.%. The antiwear properties of the oil with the addition was tested on a four-ball friction tester provided with steel balls of 12.7 mm in diameter and having Rockwell hardness of 62-64. The tests were carried out at a temperature of 200C and under a load on the shaft equal to 25,45 and 80 kg. With the load on the shaft equal to 25 kg, the rpm. of the tester was 500, the duration of the test was 1 hour; with the load on the shaft equal to 45 and 80 kg, the rpm. was 1,500 and the duration, seconds, respectively. The results of the tests are presented in the Table, from which it can be seen, that for the loads ranging within 25-80 kg, in case of using an oil with the copolymer, the diameter of the wear spot on the ball is 1.2-1.7 times less than in case of using pure oil.

EXAMPLE 2 A copolymer of ethylene with vinyltriethyltin was produced by following the same procedure as described in Example 1, in the same autoclave. The initial quantity of vinyltriethyltin was 72 g, that of di-tert.- butyl peroxide was 0.1 g. The content of vinyltriethyltin in the mixture of monomers was 35 mol.%. The duration of the copolymerization reaction was 27 minutes. After the purification there were obtained 6 g of a yellowish-grey soft sticky substance with a molecular weight of 2780. The copolymer contained 66.24 wt.% of carbon and 1 1.74 wt.%of hydrogen; the mineral residue after the combustion was 27 wt.%. The content of [CH -CHSn-(C H links in the copolymer was equal to 43.7 wt.% (8.5 mol.%). The tests of the copolymer as an antiwear addition were carried out in the same fashion as in Example 1. The results of the tests are presented in the Table.

EXAMPLE 3 A copolymer of ethylene with vinyltriethyltin was produced by following the same procedure as in Example 1. The initial quantity of vinyltriethyltin was 6 g, that of di-tert.-butyl peroxide was 0.008 g. The content of vinyltriethyltin in the mixture of monomers was 2 mol.%. The duration of the copolymerization reaction was 30 minutes. There was obtained 9.5 g of a copolymer, which was a solid white resin, more transparent than polyethylene. The copolymer contained 82.76 wt.% of carbon and 13.97 wt.% of hydrogen; the mineral residue after the combustion was 4.2 wt.%. The copolymer contained 6.6 wt.% (0.8 mol.%) of [CH- CHSn(C H links, had a molecular weight greater than 10,000, m.p. of 116C, density of 0.950 g per cu. cm., tensile strength of 130 kg per sq. cm, relative viscosity of 1.108 (for a solution of 0.035 g of the copolymer in 25 ml of decalin at C), and was easily mouldable into flexible transparent films.

EXAMPLE 4 A copolymer of ethylene with diethylmethylvinyltin was produced by following the procedure set forth in Example 1. The content of diethylmethylvinyltin in the reaction mixture was 75 g (60 mol%). The copolymerization process was initiated with the help of benzoyl peroxide, which in an amount of 0.085 g was introduced into the reaction dissolved in diethylmethylvinyltin. The copolymerization of ethylene with the organovinyltin monomer was carried out under a pres sure of 1,900 atm, at a temperature of C, during 100 minutes. There were obtained 8.7 g of the copolymer, containing 24.8 mol.% of ['CH- CHSn(C H Cl-l links. The copolymer was a white powder, soluble in benzene, xylene and in mineral oils. The properties of the copolymer as an antiwear addition to a mineral lubricating oil are illustrated in the Table.

EXAMPLE 5 A copolymer of ethylene with trimethylvinyltin was produced by techniques similar to those described in Example 1. The content of trimethylvinyltin in the reaction mixture was 23 g (8 mol.%).

The initiator of the process of copolymerization of ethylene with trimethylvinyltin was azoisobutyrodinitrile, taken in an amount of 0.25 g. The copolymerization was effected under a pressure of atm, at a temperature of 60C, during 300 minutes. There were obtained 12.4 g of the copolymer which contained 5.3 mol.% of [CH -CHSn(Cl-1 links. The copolymer was a grey soft substance, soluble in benzene, toluene and mineral oils. The properties of the copolymer as an antiwear addition are presented in the Table.

EXAMPLE 6 A rocking autoclave of 100 cu.cm. capacity was charged with a solution of 83 g of triphenylvinyltin and 0.1 g of cumene hydroperoxide as an initiator in 35 g of tetrahydrofuran as a solvent. The charging was effected in a stream of ethylene containing 0.0007 vol.% of oxygen. The content of triphenylvinyltin in the mixture of monomers was 77.8 mole.%. The copolymerization of ethylene with triphenylvinyltin was carried out under a pressure of 2,700 atm, at atemperature of 260C, during 90 minutes. The resulting copolymer was discharged and purified as described in Example 1. There were obtained 4.7 g of the product which contained 27.8 mol.% of [-CH -CHSn(C 1-1 links and was a soft brown mass, soluble in benzene, toluene and mineral oils. The properties of the copolymer as an antiwear addition are shown in the Table.

EXAMPLE 7 A copolymer of ethylene with vinylbutyldiphenyltin was produced by following the procedure described in Example 1. The content of vinylbutyldiphenyltin in the reaction mixture was 42 g (17.9 mol.%). The initiator of the process of copolymerization of ethylene with 6 as an addition to a mineral lubricating oil are presented in the Table.

Table Diameter of wear spot on ball, mm Material tested Load on Load on Load on tester tester tester shaft kg shaft 45 kg shaft 80 kg Mineral lubricating oil 0.63 0.42 2.13 Same oil containing 1 wt.% of copolymer obtained in' Example 1 0.37 0.33 1.76 Same oil containing 2.5 wt.% of copolymer obtained in Example 1 0.40 Same oil containing I wt.% of copolymer obtained in Example 2 0.36 0.34 112 Same oil containing 1 wt.% of copolymer obtained in Example 4 0.35 0.32 1.70 Same oil containing 1 wt.% of copolymer obtained in Example 5 0.42 0.33 l.89 Same oil containing l wt.% of copolymer obtained in Example 6 0.45 0.35 1.93 Same oil containing 1 wt.% of copolymer obtained in Example 7 0.29 0.31 1.62

vinylbutyldiphenyltin was di-tert.-butyl peroxide, taken in an amount of 0.065 g. The copolymerization was carried out under a pressure of 800 atm, at a temperature of 180C, during minutes. There were obtained 7.9 g of the copolymer, containing 12.4 mol.% of [CH CHSn(C 1-l C l-l links; the copolymer was a white wax-like substance, soluble in benzene, xylene and mineral oils. The properties of the copolymer containing one to six carbon atoms and phenyl. 

1. A LUBRICANT COMPOSITION WHICH COMPRISES A MAJOR AMOUNT OF A LUBRICATING OIL AND AN ETHYLENE-VINYLTIN COPOLYMER IN AMOUNT SUFFICIENT TO IMPART ANTIWEAR PROPERTIES, SAID COPOLYMER CONTAINING A MOLAR RATIO OF ETHYLENE TO VINYLTIN OF 20-98:80-2 AND SAID VINYLTIN HAVING THE FORMULA CH2=CHSN R1R2R3 WHERE R1, R2 AND R3 ARE RADICALS SELECTED FROM THE GROUP CONSISTING OF ALKYL CONTAINING ONE TO SIX CARBON ATOMS AND PHENYL. 